This video demonstrates a processing app I wrote with the intention of extracting palette information from an image or video scene. It did actually get used to pull palette info from some art images that were related to a night-club get-together that I was doing projections for.
What you see in the video is a frame from the video shown behind a 3D bar graph representing how frequently the colors show up in the frame.
For the color Savvy: the chart represents the hue and saturation of each pixel - brightness has been omitted. The center is low saturation and the edge is high; the hue changes as you move around circularly.
The takeaway is that at a quick glance you can get a decent idea of the primary color composition of your scene.